Hand trolley

ABSTRACT

A hand trolley for ascending and descending stairs is disclosed as including an elongated frame with a pair of outer rails and a pair of inner rails being spaced from the outer rails, a pair of wheels mounted on the frame at one end of the outer rails with a handle mounted on the frame at the other end of the outer rails, load supporting feet carried by the frame adjacent the wheels to define a primary load support, a carriage slidably mounted on the inner rails and defining a secondary load support, and brake shoes are operative to lock the carriage in a fixed position.

This invention has been primarily devised for the lifting andtransporting of television receivers but as will be clear from thefollowing description the trolley can be used for other equipment.

Television receivers have special features making it diffucult for asingle person to handle the larger screened models. The largertelevision receivers are very heavy, they have a fragile screen and theshape of the receiver makes it difficult to embrace them for carrying.The shape and size of the larger screened models when coupled with theirconsiderable weight makes it difficult to manoeuvre them throughconventional doorway openings. The present invention overcomes the aboveproblems.

Broadly, the invention can be said to provide a trolley comprising anelongated frame, a pair of ground engaging wheels with a common axis ofrotation located adjacent one end of the frame and projecting below theframe, a handle at the other end of the frame, a pair of first framerails occupying a common plane and extending longitudinally of the frameso as to be at right angles to the axis of rotation of the wheels, acarriage captive on said first frame rails and slidable therealong withfirst supporting means on the carriage located above the frame, secondsupporting means on the frame adjacent said one end thereof to combinewith the first supporting means to support a load when it is transportedon the trolley, stair climbing means on the trolley, said stair climbingmeans comprising two elongated sliders mounted on the frame so as to belongitudinally movable relative to the frame, resilient biassing meansbiassing the sliders towards said other end of the trolley frame againststop means with step engaging surfaces on the sliders positioned in acommon plane below said frame.

A presently preferred embodiment of the invention will now be describedwith reference to the accompanying drawings in which:

FIG. 1 is a perspective view of the trolley according to the invention,

FIG. 2 is a perspective view of the carriage of the trolley of FIG. 1,

FIG. 3 is a side view of the trolley,

FIG. 4 is an enlarged partly fragmentary perspective view of a slidermember used in the step climbing operation of the trolley,

FIG. 5 is diagrammatic view of a first position in a step climbingoperation of the trolley,

FIG. 6 is a view similar to FIG. 5 at a later stage in the step climbingoperation and

FIG. 7 is a view similar to FIG. 5 showing the last stage in the stepclimbing operation.

As illustrated the trolley comprises a frame with a body part 10 and ahandle part 11. The body part comprises a first pair of rails 12 whichare tubular and square in section and parallel and lie in a common planeand a further pair of rails 13 which are also tubular and square insection and parallel and lie in a common plane parallel to the planeoccupied by the rails 12 but lower relative to the ground, as shown inFIG. 1. The rails 12 and 13 are joined by an arched end member 14 withextended ends to provide feet 15. The handle part 11 is of U form and ismade of circular cross-section tube with the free ends of the U legspivotally connected at 16 to the rails 13 and the U legs are housed innotched lugs 17 on the rails 13. The U legs are retained in the notchesof the notched lugs 17 by means of draw bolts and cam faced levers 18both for the extended configuration where the U member provides a handleand for the folded condition where the U member legs lie closelyadjacent and parallel to the further rails 13.

At the other ends of the rails 13 there are rail extensions 20 joined bya bar 19. The axis of the bar 19 is also the axis of stub axles on whichtwo wheels 21 are rotatably mounted. There are elongated feet 22hingedly connected to the respective rail extensions 20 allowing thefeet to project at right angles to the planes occupied by the rails 12and 13 or to be folded down in a storage condition where the feet lieparallel to each other and the bar 19.

There is a carriage 23 slidably mounted on the rails 12. The carriagecomprises two sleeves or channels 24 and preferably each channel has arubbing strip of low friction plastics material such as nylon fixed tothe inner surface of the channel base. The channels are retained on therails 12 by flanged rollers 25 supported by axles 26 extending betweenthe legs of the channels. There is a mounting plate 27 positionedbetween the channels and it is pivotally supported at one end on a shaft28 passing through the two channels where it is retained by end circlipsor the like. At its other end the mounting plate 27 has a through holeto receive a shaft 28a which has its ends housed in elongated holes 29in the legs of the channels 24. Also mounted on the shaft 28 and in thechannels there are brake shoes 30 with friction material on theunderfaces to bear upon the upper faces of the rails 12. A torsionspring 31 is provided to urge the brake shoes 30 against the rails 12.

The carriage has a mounting assembly thereon comprising a suction cupholder 32 connected by a bolt to the mounting plate 27 in a mannerpermitting the holder 32 to be rotated against a friction resistancerelative to the mounting plate 27. There are two conventional suctioncups 33 with cam operating levers mounted on the holder 32. More thantwo suction cups can be used if desired.

As will be readily understood when a load is secured to the carriage bythe suction cups and the trolley is elevated so the rails are generallyupright there will be a lever action as the weight of the load tends torotate the mounting plate 27 about the rod 28. This will force the brakeshoes 30 against the rails 12 thereby locking the carriage in positionon the rails 12. This feature is of importance where, for example, atelevision receiver is to be taken from a table. The trolley would bewheeled up to the television receiver and the carriage is raised untilthe suction cups can be locked onto the screen. Then by tilting thetrolley backwards the weight of the television receiver, once free ofthe table, will cause the brake shoes 30 to bear firmly on the rails 12thereby preventing the carriage from moving down the rails 12.Subsequently the trolley would then be placed in a position where therails are parallel to the ground. By raising the mounting plate 27against the action of the torsion spring 31 the carriage can be slidalong the rails until the television receiver comes to rest on the feet22. When the trolley is raised for the transport of the televisionreceiver to a required location the weight of the television receiverwill be supported on the feet 22. The rotational capability of thesuction cup holder 32 allows the television receiver to be placed in anorientation such that it can pass through a doorway, which my not bepossible if the receiver had to maintain the orientation in which it waspicked up from a table.

The stair climbing feature of the trolley is important. There are twoelongated sliders or slider members 34 mounted on the rails 13. Eachslider has a first track or channel 35 therealong with inturned flanges36 and a second track or channel 37 therealong. The channel 35 is shapedand dimensioned to receive two rollers 38 (preferably ball bearings)mounted on pins 39 projecting sideways from the rails 13. The flanges 36prevent the sliders from lateral disengagement from the rollers 38.There are two lugged blocks 40 respectively fixed, such as by means ofrivets R or other suitable fasteners, to the rails 13 with the lugs 41thereof in the respective channels 37. A resilient member 42, either atension spring or a length of rubber or the like, is fixed to each lug41 and to the remote end of the slider 34 (in this case to a stop pin 50through the slider 34) to cause engagement between the stop pin 50 andthe adjacent roller 38. There is a second stop pin 51 through the slider34, the stop pins 50 and 51 prevent the slider from longitudinaldisengagement from the rollers, as will be clear from FIG. 4. It is tobe noted that the underfaces or lower bearing face 34' of the sliders 34are no lower, relative to the ground when the trolley is horizontal,than the points on the peripheries of the wheels 21 in contact with theground. This is a feature required for the stair climbing function ofthe trolley.

In a stair climbing operation, as shown in FIGS. 5 to 7, the wheels 21would be pulled across the tread T1 of one step until the underfaces ofthe sliders 34 rest upon the front upper edge of the next step up. Thetrolley would then be pulled rearwardly upwardly and the sliders 34, nowfirmly bearing against the step front upper edge, will remain stationarywith the rollers 38 and the blocks 40 moving with the attached trolleyframe in the direction of the arrow in FIG. 4 thereby tensioning thebiasing member 42. The intermediate stage in the step climb is shown inFIG. 6. During the upward movement of the trolley the wheels, beinglower than the sliders, will contact the step edge on which the slidersbear, as shown in FIG. 7. Continued upward rearward movement of thetrolley will result in the wheels raising the sliders 34 from the stepedge and their resilient return to their rest position with the stop pin50 bearing on the roller 38. The slider position immediately beforerelease from the step edge is shown in dotted outline and the restposition after contraction of the biasing member 42 is shown in fulllines. The trolley would then be wheeled across the tread T2 of the nextstep and the process repeated.

In a stair descending procedure the trolley would be wheeled over theedge of the step to be descended to cause the sliders to come to rest onthe step edge. The trolley frame cannot move relative to the slider 34due to the roller 38 bearing hard against the stop 50 and the result isthat the sliders slide across the edge of the step until the wheels 21come into contact the the tread T1 of the next lower step. Thefrictional resistance to movement of the slider over the step edge actsas a brake to the trolley descent which, when combined with thesmoothness of the sliding action, provides a controlled, shockless andreadily achieved descent from one step to the next. It is possible withthe use of the stair climber as described to transport heavy delicateapparatus, such as large television receivers, up and down a stairway ina shockfree manner.

I claim:
 1. A hand trolley having stair climbing means and comprising anelongated frame, a pair of ground engaging wheels mounted adjacent oneend of the frame for rotation about a common axis lateral to the lengthdirection of the frame, primary load supporting means upstanding fromthe frame adjacent said wheels, a handle at another end of the frame,two pairs of rollers fixed relative said frame with the rollers of eachsaid pairs of rollers spaced apart in the length direction of the frameand having axes of rotation parallel to each other and to the axis ofrotation of said wheels, two elongated stair climbing slider memberseach including track means extending in the length direction of theslider member, said slider members respectively movably mounted on andheld captive to said rollers of said pairs of rollers so as to bemovable from a rest position in a direction away from said handle andthereafter return to the rest position, stop means fixed to said slidermembers respectively engageable by said rollers of said pairs of rollersto define the rest position for said slider members, resilient meanshoused in said track means, said resilient means biasing said slidermembers toward said rest position, a lower bearing face on each saidslider member disposed in a plane spaced from the center of rotation ofsaid ground engaging wheels by a distance no greater than the radius ofsaid ground engaging wheels said frame including rail means in thelength direction of the frame, a carriage captive on said rail means andslidable therealong, brake means to locate said carriage at apredetermined position in its path of travel along said rail means andsecondary load support means on said carriage.
 2. A hand trolley asclaimed in claim 1 wherein said secondary load support means isrotatable on said carriage about an axis at right angle to the plane inwhich said secondary support means moves on said rail means.
 3. A handtrolley as claimed in claim 2 wherein said secondary support meansincludes load retaining suction cups.
 4. A hand trolley as claimed inclaim 4 wherein said rail means comprises two parallel rails, saidcarriage including a mounting plate, two sleeves respectively engagingsaid two rails, a pivotal connection between said mounting plate andsleeves with the axis of pivot parallel to the axis of rotation of saidground engaging wheels and at the end of said mounting plate toward saidhandle, brake shoes on said mounting plate respectively overlying saidrails and located at end of the mounting plate toward said wheels, andsaid secondary support means connected to said mounting plateintermediate said pivotal connection and said brake shoes.